1. Field of the Invention
The present invention relates to an optical disc drive, and more particularly, to an apparatus and related method for generating a tracking error signal in the optical disc drive.
2. Description of the Prior Art
Optical discs are one of various storage media used nowadays. Data can be recorded on the optical disc according to pits in the optical disc tracks. An optical disc drive utilizes a servo control system to focus a laser light outputted from a laser diode on a correct position of the track and then reads the data according to a reflection light of the laser light.
An optical sensor on a pick-up head (PUH) of the optical disc drive detects the reflected light to generate signals A, B, C, D. After generating the tracking error signal TE according to the signals A, B, C, and D, the servo control system determines whether the focus point of the laser light diverges from the track of the optical disc according to changes in the tracking error signal TE.
Since the prior art apparatus determines the phase difference between the signal A+C and the signal B+D according to the pulse width while the tracking error signal TE is being generated, when high accuracy is required for the tracking error signal TE, a high sampling rate is accordingly necessary for converting the analog signal into the digital signal, and the back end circuits must operate in a higher clock rate.